Radio Frequency Identification (RFID) technology leverages electronic data and wireless communication for identification purposes. With RFID systems, electronic data typically is stored within an RFID tag, which can be formed from a small silicon chip and one or more antennas, and affixed to a product. Reading from and/or writing to an RFID tag can be achieved through radio frequency (RF) based wireless communication via devices referred to as RFID readers. In general, writing is utilized to add and/or modify product-specific information to an RFID tag, and reading is utilized to retrieve the information, for example, to provide for automatic product identification. In many instances, the electronic data written to and/or read from an RFID tag includes an Electronic Product Code (EPC), which, in general, is a unique number that is encoded (e.g., as a bit code) and embedded within the RFID tag. Typical EPC data can include information about the associated product (e.g., product type, date of manufacture, lot number, . . . ) and/or associated pallets, boxes, cases and/or container levels, for example.
When passed through or scanned by a reader, an RFID tag emits stored electronic data such that the data can be retrieved by an RFID reader without unpacking the product or scanning barcode labels. Read information can be utilized to provide a greater degree of certainty over what goes into a supply chain and/or how to manage raw materials, warehouse inventory, shipments, logistics, and/or various other aspects of manufacturing.
One of the challenges associated with applying RFID technology is the uncertainty of whether an RFID reader antenna(s) cover the reading/writing area of a given RFID target. Since the magnetic field of an antenna is not visible, the coverage area is generally roughly estimated when positioning the antenna and it is difficult to determine and measure the signal strength without expensive tools (e.g., spectrometer equipment). Additional challenges are associated with pallet applications where there is a need to read multiple (e.g., 100 or more) RFID tags at substantially the same time. Some of the tags may be buried in the middle of a pallet with no way to physically access the tag without removing the other products on the pallet. Without a means to measure the strength of the magnetic field it is unknown if all the RFID tags on the pallet are being read. Accordingly, there is an unmet need in the art for an improved RFID system to increase system accuracy and efficiency.